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    CELLULOSE ACETATE, AND METHOD AND DEVICE FOR PRODUCING CELLULOSE ACETATE
    1.
    发明申请
    CELLULOSE ACETATE, AND METHOD AND DEVICE FOR PRODUCING CELLULOSE ACETATE 有权

    公开(公告)号：US20210017296A1

    公开(公告)日：2021-01-21

    申请号：US17060649

    申请日：2020-10-01

    Applicant: DAICEL CORPORATION

    Inventor： Akihiro KUWANA ,  Hiroaki TAMAGAKI

    IPC: C08B3/06

    Abstract: An object is to provide a cellulose acetate remarkably good in hue even when a low-quality pulp is used.
    A method for producing the cellulose acetate includes a step (1) of crushing a wood pulp, a step (2) of bringing the crushed wood pulp into contact with acetic acid to subject the pulp to pretreat the wood pulp, a step (3) of causing the wood pulp to react with acetic anhydride after the pretreatment to acetylate the pulp, a step (4) of hydrolyzing the cellulose acetate, which is yielded by the acetylation, and a step (5) of precipitating the cellulose acetate, an acetylation degree of which is adjusted by the hydrolysis. In the hydrolyzing step (4), in a hydrolysis reaction system, a concentration of oxygen is set to 3% or less.

    CELLULOSE ACETATE AND METHOD FOR PRODUCING CELLULOSE ACETATE
    5.
    发明申请
    CELLULOSE ACETATE AND METHOD FOR PRODUCING CELLULOSE ACETATE 有权

    公开(公告)号：US20210171663A1

    公开(公告)日：2021-06-10

    申请号：US16332755

    申请日：2017-09-29

    Applicant: DAICEL CORPORATION

    Inventor： Akihiro KUWANA ,  Hiroaki TAMAGAKI

    IPC: C08B3/06

    Abstract: To provide cellulose acetate that exhibits excellent hue even though it is produced by using low grade pulp having a particularly low α-cellulose content, and also achieves excellent moldability and excellent production efficiency of a molded article. A method for producing cellulose acetate is also provided, the method that can provide cellulose acetate with excellent stable productivity and production efficiency without passing through steps such as extraction. The cellulose acetate of the present invention includes xylose with a molar content rate of greater than 7.0 mol % and not greater than 15 mol % in a sum of molar contents of xylose, mannose, and glucose; and has a hue of not less than 0.60 cm−1 and less than 0.80 cm−1 at a wavelength of 430 nm by absorptiometry; and a 6% viscosity of not greater than 160 mPa·s.

    CELLULOSE ACETATE, AND METHOD AND DEVICE FOR PRODUCING CELLULOSE ACETATE
    6.
    发明申请
    CELLULOSE ACETATE, AND METHOD AND DEVICE FOR PRODUCING CELLULOSE ACETATE 审中-公开

    公开(公告)号：US20180282434A1

    公开(公告)日：2018-10-04

    申请号：US15766672

    申请日：2016-10-05

    Applicant: DAICEL CORPORATION

    Inventor： Akihiro KUWANA ,  Hiroaki TAMAGAKI

    IPC: C08B3/06

    Abstract: An object is to provide a cellulose acetate remarkably good in hue even when a low-quality pulp is used.A method for producing the cellulose acetate includes a step (1) of crushing a wood pulp, a step (2) of bringing the crushed wood pulp into contact with acetic acid to subject the pulp to pretreat the wood pulp, a step (3) of causing the wood pulp to react with acetic anhydride after the pretreatment to acetylate the pulp, a step (4) of hydrolyzing the cellulose acetate, which is yielded by the acetylation, and a step (5) of precipitating the cellulose acetate, an acetylation degree of which is adjusted by the hydrolysis. In the hydrolyzing step (4), in a hydrolysis reaction system, a concentration of oxygen is set to 3% or less.

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